Question

If $5x^{2} + \lambda y^{2} = 20$ represents a rectangular hyperbola, then $\lambda$ equals

• A. 5
• B. 4
• C. – 5
• D. None of these

Answer 1

Answer: (C)

– 5

Answer 2

Since the general equation of second degree represents a rectagular hyperbola if $\Delta \neq 0,h^{2} > ab$ and coefficient of $x^{2} +$coefficient of $y^{2} = 0$. Therefore the given equation represents a rectangular hyperbola if $\lambda + 5 = 0$ i.e., $\lambda = - 5$